Gang-type lawn mower

ABSTRACT

A mower includes a frame, at least one cutting unit, and a lifting unit. The lifting unit is connected to the at least one cutting unit and includes a yoke assembly, a first arm assembly, a second arm assembly, and a third arm assembly. The yoke assembly is connected to the cutting unit. The first arm assembly is pivotably mounted to the vehicle frame about a first pivot axis. The second arm assembly is pivotably mounted to the first arm assembly about a second pivot axis and to the yoke assembly about a third pivot axis with the second pivot axis and third pivot axis being non-parallel to the first pivot axis. The third arm assembly includes a first end pivotally connected to the frame and a second end pivotally connected to the second arm assembly.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/105,777 filed on Nov. 27, 2020, which is a continuation of U.S.patent application Ser. No. 16/270,117, filed on Feb. 7, 2019. Thedisclosures of the above applications are incorporated herein byreference in their entirety.

TECHNICAL FIELD

The invention relates generally to gang-type lawn mower and inparticular to a lift geometry for one or more of the cutting unitsutilized in a gang-type lawn mower.

BACKGROUND

Gang-type lawn mowers are characterized by a plurality of rotary cuttingdecks. For example, some gang-type rotary mowers include a front row oftwo or more cutting decks forward of the front wheels and a rear row oftwo or more cutting decks located between the front wheels and the rearwheels, wherein at least a portion of the one or more cutting decksextends laterally beyond the wheels of the mower to maximize the cuttingwidth. During transport the outer cutting decks are lifted vertically tominimize the width of the mower. It would be desirable to provide alifting geometry that optimizes the location of the cutting deck in boththe lowered position and raised position.

SUMMARY

According to one aspect, a gang-type mower includes a frame, at leastone cutting unit, and a lifting unit. The lifting unit is connected tothe at least one cutting unit and includes a yoke assembly, a first armassembly, a second arm assembly, and a third arm assembly. The yokeassembly is connected to the cutting unit. The first arm assembly ispivotably mounted to the vehicle frame about a first pivot axis. Thesecond arm assembly is pivotably mounted to the first arm assembly abouta second pivot axis and to the yoke assembly about a third pivot axiswith the second pivot axis and third pivot axis being nonparallel to thefirst pivot axis. The third arm assembly includes a first end pivotallyconnected to the frame and a second end pivotally connected to thesecond arm assembly.

According to another aspect, a lifting unit comprises a yoke assembly, afirst arm assembly, a second arm assembly, and a third arm assembly. Thefirst arm assembly includes a first end and a second end, wherein thefirst arm assembly includes apertures configured to pivotally affix thefirst arm assembly to a stationary frame about a first pivot axis. Thesecond arm assembly includes a first end and a second end, wherein thefirst end is pivotably connected to the second end of the first armassembly about a second pivot axis and wherein the second end ispivotally connected to the yoke assembly about a third pivot axis,wherein the second pivot axis and third pivot axis are non-parallel tothe first pivot axis. The third arm assembly includes a first endconfigured to pivotally connect the third arm assembly to the stationaryframe and a second end pivotally connected to the second arm assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of a gang-type lawn mower according to someembodiments.

FIGS. 2A and 2B are side views of the gang-type lawn mower with theculling decks in a lowered and raised positions, respectively, accordingto some embodiments.

FIG. 3A is an isometric view of a lifting unit in the lowered position,FIG. 3B is another isometric view of the lifting unit in the loweredposition, and FIG. 3C is side view of the lifting unit in the loweredposition according to some embodiments.

FIG. 4A is an isometric view of a lifting unit in a raised position,FIG. 4B is another isometric view of the lifting unit in the raisedposition, and FIG. 4C is side view of the lifting unit in the raisedposition according to some embodiments.

FIG. 5 is an exploded view of the lifting unit according to someembodiments.

DETAILED DESCRIPTION

The present disclosure provides a gang-type lawn or turf mower having aplurality of cutting decks. At least one of the cutting decks isconnected to a frame or chassis of the mower via a lift unit that liftsthe cutting deck from a first position to a second position. Inparticular, the lift unit moves the cutting deck both vertically(z-direction) and longitudinally (y-direction) when moving from thefirst position to the second position. To provide both vertical andlongitudinal movement the lift unit includes a first arm assemblyconnected to the frame at one end and to a second arm assembly on asecond end, wherein the first arm assembly pivots about a first axislocated between the first end and the second end. The second armassembly includes a first end and a second end, wherein the first end ispivotally connected to the first arm assembly and the second end ispivotally connected to a yolk assembly that in turn supports the cuttingdeck. A third arm assembly is connected between a fixed location (e.g.,frame) and the second arm assembly. To raise the cutting deck the firstarm assembly is pivoted about the first axis. As the cutting deck israised vertically (in the z-direction), the second arm assembly isallowed to pivot at both the first and second ends to move the cuttingdeck longitudinally (e.g., in the y-direction or rearward) as dictatedby the connection of the third arm assembly to the second arm assembly.

Referring now to FIGS. 1, 2A and 2B, a gang-type rotary lawn or turfmower 100 is shown. FIG. 2A is a side view that illustrates a cuttingdeck 116 a in the first position (i.e., lowered position) and FIG. 2B isa side view that illustrates the cutting deck 116 a in the second orraised position. In some embodiments, the gang-type lawn or turf mower100 includes engine cover/hood 102, a plurality of ground-engagingmembers 104, seat 106, roll-over protection bar 108, steering wheel 110,footrest 112, a plurality of forward cutting decks 114 a, 114 b, and 114c and a plurality of rear cutting decks 116 a, 116 b, and 116 d (one ofwhich is hidden from view). The ground engaging members 104 areoperatively connected to the frame or chassis of the mower 100 and atleast one of the ground engagement members 104 is driven by a primemover of the mower 100 (e.g., an internal combustion engine or anelectric motor) to propel the mower over the ground. In someembodiments, the front row includes three cutting decks 114 a, 114 b,and 114 c and the back row includes four cutting decks, wherein cuttingdecks 116 a, 116 b, and 116 d are visible. in the embodiment shown inFIG. 1 , each of the cutting decks 116 a, 11.6 b, and 116 d is in thefirst position (i.e., lowered position).

As illustrated in FIGS. 2A and 2B, the cutting deck 116 a moves rearwardalong the y-axis when raised from the first position to the secondposition. As shown in FIG. 2A, a forward cutting edge of cutting deck116 a is marked by dashed line I₁, which is located forward of roll-overprotection bar 108 and approximately equal with the operator's seat 106.In the second or raised position—shown in FIG. 2B—the forward cuttingedge of cutting deck 116 a is marked by dashed line I₂, which is locatedrearward of the operator seat 106 and roll-over protection bar 108. Inthis way, at least a portion of the cutting deck 116 a is locatedadjacent to the operator seat 106 in the first, lowered position andlocated rearward of the operator seat 106 in the second, raisedposition. In the embodiment shown in FIG. 2B, cutting deck 116 a islocated rearward of the operator seat 106 when in the second/raisedposition, and approximately adjacent to the operator seat 106 when inthe first/lowered position. In some embodiments, having the cutting deck116 a move rearward when moved into the second/raised position allowsthe operator to exit the vehicle more easily. It should be understoodthat although not illustrated in FIGS. 2A and 2B, the cutting deck 116 dmoves between the first/lowered position and the second/raised positionin substantially the same manner, function and operation. In otherembodiments, the cutting decks 116 a and 116 d can be moved forwardalong the y-axis rather than rearward depending on the configuration ofthe vehicle.

Referring now to FIGS. 3A-3C and 4A-4C, a lifting unit 200 is shown inboth the first/lowered position (FIGS. 3A-3C) and the second/raisedposition (FIGS. 4A-4C), also sometimes referred to as the transportposition. In particular, FIG. 3A is an isometric view of the liftingunit 200 that would be utilized on the right side of the gang-type lawnmower 100 and FIG. 3B is an isometric view of the lifting unit 200 thatwould be utilized on the left side of the gang-type lawn mower 100. Thelifting unit 200 utilized on the left side of the mower is substantiallythe same as the lifting unit 200 utilized on the right side, and thesame numbers are utilized for components on each. In addition, FIG. 3Cis a side view of the lifting unit 200 in the lowered position. FIGS.4A-4C utilize the same views shown in FIGS. 3A-3C, but with the liftingunit in the second or raised position.

In some embodiments, the lifting unit 200 includes a lifting frameassembly 202, a first arm assembly 204, a second arm assembly 206, athird arm assembly 208, and a yoke assembly 210. Lifting frame assembly202 includes bracket 212, vertical support 214 a, 214 b, lifting framearms 216 a, 216 b, frame cross member 218, and third arm assembly framesupport 220. Lifting frame assembly 202 is stationary and is connectedbetween the frame of the vehicle (not shown) and the components utilizedto lift the cutting deck 116. The components of lifting frame assembly202 can be connected to one another via fasteners, weldments, or otherwell-known means of affixing components together. Referring to FIG. 2A,lifting frame assembly 202 is coupled to mower frame via one or morefasteners and/or weldment. In particular, bracket 212 is utilized tosecure the lifting frame assembly 202 to the mower frame/chassis and islocated rearward of both the operator's seat 106 and the roll-overprotection bar 108.

In some embodiments, first arm assembly 204 includes first and secondarms 222 a and 222 b, which each include first ends 224 a, 224 b andsecond end 226. Second arm assembly 206 includes first and second arms228 a, 228 b. Third arm assembly 208 includes gas spring 232, arm 234, afirst end 236 a containing a first ball joint connection, and a secondend 236 b containing a second ball joint connection. Yoke assembly 210includes mounting bracket 230, first and second arms 240 a, 240 b,connection ends 242 a, 242 b, strike plate 244.

In some embodiments, the first arm assembly 204 is pivotally affixed tothe frame assembly 202. For example, pivot first axis ‘a’ shown in FIG.3C illustrates the pivotal connection between the first arm assembly 204and the frame assembly 202. In the embodiment shown in FIG. 3C, firstand second brackets 215 a, 215 b of the lifting frame assembly 202 arepivotally connected to first arm assembly 204, and in particular tofirst and second arms 222 a and 222 b of first arm assembly 204. Thefirst ends 224 a, 224 b of first arm assembly 204 are pivotallyconnected to hydraulic cylinder 246 and the second end 226 includes apivotal mounting bracket 227 for pivotally connecting the first armassembly 204 to the second arm assembly 206. To raise the yoke assembly210 (and therefore the cutting decks 116 a and 116 b) the hydrauliccylinder 246 is actuated or extended in length to pivot first armassembly 204 about the first pivot axis ‘a’. For example, FIG. 3Cillustrates the hydraulic cylinder 246 in a non-actuated or non-extendedstate, in which yoke assembly 210 is in the first/lowered position. FIG.4C illustrates the hydraulic cylinder 246 in the actuated or extendedstate, in which first arm assembly 204 is pivoted about the first pivotaxis ‘a’, causing the second arm assembly 208 and yoke assembly 210 tobe raised vertically. In some embodiments, first pivot axis ‘a’ extendsin an approximately longitudinal direction (e.g., y-direction or intothe page in FIGS. 3C and 4C).

In some embodiments, the second arm assembly 206 includes one or morearms 228 a, 228 b pivotally connected to the first arm assembly 204 onone end and pivotally connected to the yoke assembly 210 on an oppositeend. In the embodiment shown in FIGS. 3A-3C, first and second arms 228 aand 228 b are each pivotally connected to the pivotal mounting bracket227 of first arm assembly 204, and pivot about second pivot axes b₃ andb₄. In some embodiments, first and second arms 228 a and 228 b are alsopivotally connected to mounting bracket 230 associated with yokeassembly 210, and pivot about third pivot axes b₁ and b₂. As shown inFIG. 3C, the orientation of pivot axes b₁, b₂, b₃, and b₄ isnon-parallel to that of axis ‘a’. As the cutting deck is raised/lowered,the orientation of pivot axis b₁, b₂, b₃, and b₄ is modified from anapproximately vertical orientation (shown in FIG. 3C) to anapproximately horizontal orientation (shown in FIG. 4C), but remainsnon-parallel to that of first pivot axis ‘a’. In some embodiments, thepivot axes b₁, b₂, b₃, and b₄ are approximately perpendicular to theaxis ‘a’. The pivotal connection of the second arm assembly 206 to boththe first arm assembly 204 and to the yoke assembly 210 allows the yokeassembly 210 to be moved in a longitudinal direction (e.g., along they-axis) during vertical movement of the cutting deck. For example, asshown in FIG. 3B, when in the lowered position the first and second arms228 a and 228 b extend outward from the first arm assembly 204approximately perpendicular to the axis ‘a’. As shown in FIGS. 4A and4B, when in the raised position the first and second arms 228 a and 228b are allowed to pivot about axes b₁, b₂, b₃, and b₄ such that first andsecond arms 228 a and 228 b extend outward from first arm assembly 204in a direction that is not perpendicular to the axis ‘a’. For example,in the embodiment shown in FIGS. 4A and 4B, first and second arms 228 aand 228 b of second arm assembly 206 extend rearwardly from the firstarm assembly 204, resulting in the yoke assembly 210 moving in arearward direction as compared with the location of the yoke assembly210 in the lowered position.

The rearward movement of the yoke assembly 210 is made possible by thepivotal connection of the second arm assembly 206 to the first armassembly 204 and by the pivotal connection of the second arm assembly206 to the yoke assembly 210, which is controlled by the third assembly208. As shown in FIGS. 3A-3C, the third arm assembly 208 includes afirst end 236 a pivotally affixed to the frame assembly 202 and a secondend 236 b pivotally connected to the one of the arms (e.g., first arm228 a) of second arm assembly 206. In the embodiment shown in FIGS.3A-3C and 4A-4C the third arm assembly 208 is connected to first arm 228a of the second arm assembly 206. In some embodiments, the length ofthird arm assembly 208 is constant (or relatively constant). As thefirst arm assembly 204 is actuated, causing the second arm assembly tomove vertically upward, the third arm assembly causes the second armassembly to pivot about axes b₁, b₂, b₃, and b₄. As a result, the distalend of second arm assembly 206 is caused to move rearward along they-axis during the lifting operation.

The position of the third arm assembly 208 dictates the direction inwhich the yoke assembly (and cutting deck 116) is moved (e.g., forward,rearward) during lifting operations. In some embodiments, such as thoseshown in FIGS. 3A-3C and 4A-4C the third arm assembly 208 is connectedto the third arm assembly frame support 220 forward of the connectionbetween first arm assembly 204 and second arm assembly 206. As a resultof the placement of third arm assembly 208 relative to the first andsecond arm assemblies 204 and 206, the yoke assembly 210 and cuttingdeck 116 is moved rearward as the cutting deck 116 is lifted verticallyupward. In other embodiments, the third arm assembly 208 can beconnected to the frame support rearward of the connection between firstarm assembly 204 and second arm assembly 206. In some embodiments, thedistal end 236 b of third arm assembly 208 is connected to the secondarm assembly 206 more than halfway along the length of the second armassembly 206 (as shown in FIG. 3C, for example). In other embodiments,the distal end 236 b of third arm assembly 208 can be connected to thesecond arm assembly 206 at various points along the length of the secondarm assembly 206. The location at which the third arm assembly 208 isconnected to the frame assembly 202 and to the second arm assembly 206determines, in part, the length of forward/rearward travel of the yokeassembly 210 and cutting unit 116 during lifting operations.

In some embodiments, first and second ends 236 a and 236 b of the thirdarm assembly 208 includes a ball joint connection to allow limitedmovement of the joint in a number of different directions. In otherembodiments, other types of pivotal connections can be utilized toconnect the third arm assembly 208 to the second arm assembly 206 and/orto the frame to allow the desired range of motion. In some embodiments,third arm assembly 208 further includes a gas spring 232 and an arm 234.The inclusion of gas spring 232 allows the cutting assembly 116 (e.g.,cutting assembly 116 a and/or 116 d) to move in a lateral direction(approximately along the x-axis) in response to foreign objects (e.g.,rocks) coming into contact with the cutting assembly 116 while in thelowered position.

In some embodiments the yoke assembly 210 includes first and second arms240 a and 240 b extending away from mounting tube 231. First and secondarms 240 a and 240 b include connection ends 242 a and 242 b for rigidlyconnecting the yoke assembly 210 to the cutting unit 116. In someembodiments, yoke assembly 210 further includes a strike plate 244affixed to one of the arms 240 a or 240 b. For example, in theembodiment shown in FIG. 3A the strike plate 244 includes a firstportion extending approximately horizontally from the yoke assembly 210and a second, bent portion. The bent portion is configured to come intocontact with a contact plate 248 affixed to the second arm assembly 206when the yoke assembly 210 is in the raised position. In someembodiments, the geometry of strike plate 244 acts to prevent the yokeassembly 210 from binding with second arm assembly 206 when in theraised position. The strike plate 244 acts to guide the yoke assembly210 away from the second arm assembly 206. In some embodiments, yokeassembly 210 further includes a hose hangar 250 affixed to one of thefirst or second arms 240 a, 240 b.

Referring now to FIG. 5 , an exploded view of the lifting unit 200according to some embodiments is shown. In particular, FIG. 5illustrates according to some embodiments the connection of the variouscomponents to one another. While particular structures are described forconnecting the components to one another, it should be understood thatvarious other means of connecting the components to one another can beutilized. For the sake of simplicity, a single numeric identifier isutilized for components of a same type (e.g., bolts, washers) allfasteners of this type, although it is understood that each componentcan vary in size/shape depending on the application.

In some embodiments, lifting frame assembly 202 includes bracket 212,vertical supports 214 a, 214 b, first and second brackets 215 a, 215 b,lifting frame arms 216 a, 216 b, frame cross member 218, third arm framesupport 220. The first arm assembly 204 is pivotally connected to thefirst and second brackets 215 a, 215 b of the lifting frame assembly202. As shown in FIG. 5 , a lift pin 414 is provided through an aperturein first bracket 215 a, through apertures in the first arm assembly 204(for example, in arms 222 a, 222 b of first arm assembly 204, as shownin FIGS. 3A and 4B, above), the aperture in second bracket 215 b andsecured by cam bracket 438 to allow first arm assembly 204 to pivotabout lift pin 414. For example, pivot axis ‘a’ would extend throughlift pin 414.

In some embodiments, first arm assembly 204 is pivotally affixed tohydraulic cylinder 246 via locking pin 415. As shown in FIGS. 3A and 3C,first arm assembly 204 includes first and second arms 222 a and 222 b,each of which includes a first end 224 having apertures for receivingthe locking pin 415. The distal end of hydraulic cylinder 246 includesan aperture 444 that is configured to fit within the first and secondarms 222 a and 222 b such that the apertures of each are aligned,allowing locking pin 415 to be inserted through both the distal end 444of the hydraulic cylinder 246 positioned between the first and secondarms 222 a, 222 b of first arm assembly 204, and apertures in both arealigned to allow locking pin 415 to be secured in each. Washers 410 andlocking washers 417 are utilized on each end of locking pin 415 to holdthe locking pin in place and pivotally connect a distal end of thehydraulic cylinder to the first arm assembly 204. Actuation of hydrauliccylinder 246 exerts force on the first ends 224 a, 224 b of the firstarm assembly 204. In some embodiments, a second end 446 of the hydrauliccylinder 246 is located opposite of the first end 444, and is securedvia pin 412, washers 410 and lock washers 417 to the frame (not shown).

In some embodiments, first arm assembly 204 is coupled to second armassembly 206 via first and second inner lift pins 426 a, 426 b. Secondend 226 of first arm assembly 204 includes two pair of apertures (topand bottom) for receiving first and second inner lift pins 426. Thefirst inner lift pin 426 a extends through a top aperture associatedwith the first arm assembly 204, through an aperture associated withsecond arm 228 a of second arm assembly 206, and through a bottomaperture associated with the first arm assembly 204, allowing arm 228 aof second arm assembly 206 to pivot around first inner lift pin 426 a.Likewise, the second inner lift pin 426 b extends through a top apertureassociated with the first arm assembly 204, through an apertureassociated with second arm 228 b of second arm assembly 206, and througha bottom aperture associated with the first arm assembly 204, allowingarm 228 b of second arm assembly 206 to pivot around second inner liftpin 426 b. In some embodiments, the inner lift pins 426 a and 426 b aresecured to the second end 226 of first arm assembly 204 via a bolt thatextends through an aperture in first inner lift pin 426 a, apertures inthe second end 226 of first arm assembly 204, and through an aperture insecond inner lift pin 426 b, secured by a nut 422.

In some embodiments, second arm assembly 206 is coupled to yoke assembly210 via first and second outer lift pins 428 a and 428 b. Mountingbracket 230 of yoke assembly 210 includes two pair of apertures (top andbottom) for receiving first and second outer lift pins 428 a and 428 b.The first outer lift pin 428 a extends through a top aperture associatedwith the mounting bracket 230, through an aperture 454 a associated withsecond arm 228 a of second arm assembly 206, and through a bottomaperture associated with the mounting bracket 230, allowing arm 228 a ofsecond arm assembly 206 to pivot around first outer lift pin 428 a.Likewise, the second outer lift pin 428 b extends through a top apertureassociated with the mounting bracket 230, through an aperture 454 bassociated with second arm 228 b of second arm assembly 206, and througha bottom aperture associated with the mounting bracket 230, allowing arm228 b of second arm assembly 206 to pivot around second outer lift pin428 b. In some embodiments, the outer lift pins 428 a and 428 b aresecured to the mounting bracket 230 of yoke assembly 210 via a bolt 406that extends through an aperture in first outer lift pin 428 a,apertures in the mounting bracket 230 of yoke assembly 210, and throughan aperture in second outer lift pin 428 b, secured by a nut 422.

In some embodiments, mounting bracket 230 is attached to mounting tube231. In some embodiments, mounting bracket 230 is welded or otherwiseaffixed to mounting tube 231. In some embodiments, mounting tube 231includes a first portion having a first radius and a second portionhaving a second radius smaller than the first radius. In someembodiments, the second portion 450 of mounting tube 231 has a radiusconfigured to fit within the mounting tube 452 associated with first andsecond arms 240 a and 240 b of yoke assembly 210. In some embodiments,the second portion 450 extends through the mounting tube 452 and iscaptured by washer 410, ring 411 and plug 420. In some embodiments, ring411 is a snap ring that is configured to snap into a groove associatedwith the second portion 450 of mounting tube 231, wherein a portion ofsnap ring 411 extends beyond the radius of the second portion 450 tocapture the second portion 450 within the mounting tube 452.

In some embodiments, wire hose support 250 is secured via a fastener tofirst arm 240 a of yoke assembly 210. In the embodiment shown in FIG. 5the fastener includes bolt 406, a pair of washers 410 and a nut 422. Insome embodiments, strike plate 244 is secured via a fastener to secondarm 240 b of yoke assembly 210. In the embodiment shown in FIG. 5 thefastener includes a pair of bolts 406, washers 410 and nuts 422. Asdescribed above, when the cutting deck 116 (e.g., cutting decks 116 a or116 d) is in the raised configuration the strike plate 244 comes intocontact with the contact plate 248 connected to second arm assembly 206.A magnified view of the area identified as “A” is shown in the insert,which illustrates the connection of contact plate 248 with second arm228 b of second arm assembly 206. In some embodiments, two or morefasteners are utilized to secure the contact plate 248 with the secondarm 228 b of the second arm assembly 206. For example, in someembodiments, a pair of nutsets 418, washer 410, lock washers 417, andbolts 406 are utilized to secure the contact plate 248 to the second armassembly 206. In some embodiments, contact plate 248 includes twocounter sinks to ensure that the heads of bolts 406 do not interferewith the contact between contact plate 248 and strike plate 244.

In some embodiments, third arm assembly 208 is coupled to first arm 228a of second arm assembly 206 on one end and to the lifting frameassembly 202 on the opposite end. In some embodiments, third armassembly 208 includes gas spring 232, arm 234, tie rod 235, first end236 a containing the first ball joint connection and a second end 236 bcontaining the second ball joint connection, wherein third arm assembly208 is pivotally fastened to second arm assembly 206 via the second balljoint. In the embodiment shown in FIG. 5 , a bolt 406 and nut 422 areutilized to fasten first ball joint to the first arm 228 a of second armassembly 206, wherein a spacer 424 is utilized to maintain space betweenthird arm assembly 208 and second arm assembly 206. In some embodiments,the spacer 424 allows third arm assembly 208 to pivot relative to secondarm assembly 206 within contact between the respective arm assemblies.In some embodiments, third arm assembly 208 is further coupled to astationary point associated with the lifting frame assembly 202. In someembodiments, mounting bracket 402 is affixed to lifting frame assembly202 via one or more of weldments and/or fasteners, and third armassembly 208 is pivotally fastened to the mounting bracket 402 via thefirst ball joint. In the embodiment shown in FIG. 5 , a bolt 406 and nut422 are utilized to fasten the second ball joint to the mounting bracket402. In some embodiments a rubber stop 432 is affixed to mountingbracket 402, wherein the second arm 240 b of the yoke assembly 210 comesinto contact with the rubber stop 432 when the cutting deck is in theraised position.

In some embodiments, a stop bracket 404 is affixed to the lifting frameassembly 202. In some embodiments, stop bracket 404 can be welded and/orfastened to the lifting frame assembly 202. For example, in theembodiment shown in FIG. 5 the stop bracket 404 is fastened via aplurality of screws 408 to an outer surface of second bracket 215 aassociated with lifting frame assembly 202. In some embodiments, arubber stop 432 is affixed or otherwise fastened to a surface of thestop bracket 404, wherein the rubber stop 432 comes into contact withthe first arm 228 a of the second arm assembly 206 when the cutting deckis in the raised position.

While the invention has been described with reference to an exemplaryembodiment(s), it will be understood by those skilled in the art thatvarious changes can be made and equivalents can be substituted forelements thereof without departing from the scope of the invention. Inaddition, many modifications can be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment(s) disclosed, but that theinvention will include all embodiments falling within the scope of theappended claims.

What is claimed is:
 1. A lifting unit operatively connecting a cuttingunit to the chassis of a turf mower, the lifting unit comprising: alifting frame assembly connected to mower chassis; a first arm assemblypivotably mounted to the lifting frame assembly about a first pivotaxis; a second arm assembly pivotably mounted to the first arm assemblyabout a second pivot axis; a third arm assembly having a first endpivotally connected to the lifting frame assembly and a second endpivotally connected to the second arm assembly; and a yoke assemblypivotally connected to the second arm assembly about a third pivot axisand pivotally connected to the cutting unit, wherein the lifting unit isstructured and operable to move the cutting unit between a loweredposition and raised position, and wherein the second pivot axis andthird pivot axis being non-parallel to the first pivot axis.
 2. Thelifting unit of claim 1, wherein the second arm assembly includes afirst arm and a second arm, wherein each of the first arm and the secondarm include a first end pivotally connected to the first arm assemblyand a second end pivotally connected to the yoke assembly.
 3. Thelifting unit of claim 2, wherein the first arm and the second arm remainparallel to one another in both the lowered position and the raisedposition.
 4. The lifting unit of claim 2, wherein the first end of thethird arm assembly is pivotally coupled to the lifting frame assemblyforward of where the second arm assembly pivotably mounts to the firstarm assembly.
 5. The lifting unit of claim 4, wherein the second end ofthe third arm assembly is pivotally connected to the second arm of thesecond arm assembly, and wherein the second arm of the second armassembly is located rearward of the first arm of the second armassembly.
 6. The lifting unit of claim 1 further comprising a hydrauliccylinder connected between the lifting frame assembly and a first end ofthe first arm assembly, wherein the hydraulic cylinder is actuated toraise the cutting unit from the lowered position to the raised position.7. The lifting unit of claim 1, wherein the second pivot axis and thethird pivot are approximately perpendicular to the first pivot axis whenthe cutting unit is in both the lowered and raised position.
 8. Thelifting unit of claim 1 wherein the first end of the third arm assemblyis secured to the lifting frame assembly at a location offset from wherethe first end of the second arm is pivotally mounted to the first armassembly in one of a longitudinally forward or rearward direction.
 9. Aturf mower, said mower comprising: a chassis supported by a plurality ofground engagement members; a cutting unit; and a lifting unitoperatively connecting the cutting unit to the chassis, the lifting unitcomprising: a lifting frame assembly connected to mower chassis; a firstarm assembly pivotably mounted to the lifting frame assembly about afirst pivot axis; a second arm assembly pivotably mounted to the firstarm assembly about a second pivot axis; a third arm assembly having afirst end pivotally connected to the lifting frame assembly and a secondend pivotally connected to the second arm assembly; and a yoke assemblypivotally connected to the second arm assembly about a third pivot axisand pivotally connected to the cutting unit, wherein the lifting unit isstructured and operable to move the cutting unit between a loweredposition and raised position, and wherein the second pivot axis andthird pivot axis being non-parallel to the first pivot axis.
 10. Themower of claim 9, wherein the second arm assembly includes a first armand a second arm, wherein each of the first arm and the second arminclude a first end pivotally connected to the first arm assembly and asecond end pivotally connected to the yoke assembly.
 11. The mower ofclaim 10, wherein the first arm and the second arm remain parallel toone another in both the lowered position and the raised position. 12.The mower of claim 10, wherein the first end of the third arm assemblyis pivotally coupled to the lifting frame assembly forward of where thesecond arm assembly pivotably mounts to the first arm assembly.
 13. Themower of claim 12, wherein the second end of the third arm assembly ispivotally connected to the second arm of the second arm assembly,wherein the second arm of the second arm assembly is located rearward ofthe first arm of the second arm assembly.
 14. The mower of claim 9further comprising a hydraulic cylinder connected between the liftingframe assembly and a first end of the first arm assembly, wherein thehydraulic cylinder is actuated to raise the cutting unit from thelowered position to the raised position.
 15. The mower of claim 9,wherein the second pivot axis and the third pivot are approximatelyperpendicular to the first pivot axis when the cutting unit is in boththe lowered and raised position.
 16. The mower of claim 9 furthercomprising a roll over protection bar located rearward of the operatorseat, wherein a forward cutting edge of the cutting unit is locatedforward of the roll over protection bar when in the lowered position andwherein the forward edge of the cutting unit is located rearward of theroll over protection bar when in the raised position.
 17. The mower ofclaim 9 wherein the first end of the third arm assembly is secured tothe lifting frame assembly at a location offset from where the first endof the second arm is pivotally mounted to the first arm assembly in oneof a longitudinally forward or rearward direction.
 18. A lifting unitoperatively connecting a cutting unit to the chassis of a turf mower,the lifting unit comprising: a lifting frame assembly connected to mowerchassis; a first arm assembly pivotably mounted to the lifting frameassembly about a first pivot axis; a second arm assembly pivotablymounted to the first arm assembly about a second pivot axis; a third armassembly having a first end pivotally connected to the lifting frameassembly and a second end pivotally connected to the second armassembly; and a yoke assembly pivotally connected to the second armassembly about a third pivot axis and pivotally connected to the cuttingunit, wherein the lifting unit is structured and operable to move thecutting unit between a lowered position and raised position, and whereinthe second pivot axis and third pivot axis being non-parallel to thefirst pivot axis, and wherein the second pivot axis and the third pivotare approximately perpendicular to the first pivot axis when the cuttingunit is in both the lowered and raised position.
 19. The lifting unit ofclaim 18 wherein when the cutting unit is in the lowered position aforward edge of the cutting unit is located forward of a roll overprotection bar of the turf mower when in the raised position the forwardedge of the cutting unit is located rearward of the roll over protectionbar.
 20. The lifting unit of claim 1 wherein the first end of the thirdarm assembly is secured to the lifting frame assembly at a locationoffset from where the first end of the second arm is pivotally mountedto the first arm assembly in one of a longitudinally forward or rearwarddirection.